We are studying the effects of raising animals in deprived visual environments on the receptive fields of cells in the superior colliculus and visual cortex. We have studied animals raised with artificial squint, alternating monocular occluders and a combination of artificial squint and alternating monocular occlusion. We have found that while all three conditions produce, as previously reported, a visual cortex in which most cells are monocularly driven, they produce a superior colliculus in which most cells are binocularly driven. The dominance of the normal or unoperated eye, so prominent in the colliculus of animals raised with artificial squint, disappears when alternating occlusion forces the animal to use the operated eye on alternate days. We are also studying the time course of the corticical effects of alternating monocular occlusion. Raising animals with normal binouclar vision for a large portion of the critical period, up to 8 weeks of age, does not prevent 21 days of alternating monocular occlusion from creating a visual cortex in which most cells are monocularly driven. We are currently studying the effects of alternating occlusion for only a few days during the height of the critical period. Finally, we plan to study the behavior of single cells in the superior colliculus of alert primates while the animals are making eye movements in response to visual and auditory stimuli. BIBLIOGRAPHIC REFERENCES: Gordon, Barbara and Gummow, Linda. The effects of extraocular muscle section on receptive fields in cat superior colliculus. Vis. Res. 15:1011-1020 (1975). Gordon, Barbara, Gummow, Linda and Presson, Joelle. Effects of extraocular muscle surgery and alternating monocular occlusion on receptive fields in cat superior colliculus. Abstract, Society for Neurosciences, 1975.